Powered, motorized prosthetics enable users to more naturally perform tasks, such as climbing stairs or rising from a seated position. However because the power requirements fluctuate during the gait cycle; the current battery system is not energy efficient and also since energy is dissipated through a shunt resistor when the motor slows and changes direction. As a result the battery is (over)designed to accommodate necessary spikes in power draw. Improvements to the power system to efficiently recover energy and provide power spikes would enable smaller, lighter prostheses with longer use on one battery charge. The overall objective of the Fast Track Phase I/II SBIR program is to develop energy storage device, containing Giner?s tailored Lithium Ion Battery (LIB) and solid-state capacitor, specifically designed to harvest energy pulses generated during braking of the joint motors in a powered prosthetic. Giner?s proposed Battery- Capacitor Hybrid (BCH) will propel a transfemoral amputee at least 10,000 steps, on a single charge in a powered leg prosthetic, and will extend device use during more energy intensive actions, such as running or jumping. Extending operational range and providing rapid recharge capability will reduce range anxiety, improve health, and raise quality of life for amputees. Generally, these advances will increase the adoption of powered prosthetic limbs. Phase I will identify, validate key advantages, and fabricate a bench top BCH module for a powered leg prosthetic that can regenerate energy within gait cycles and operate for ? 10,000 steps on a single charge. The scope of the work for the Phase II will include further refinement of the BCH components as well as designing, building, and testing full-scale integrated BCH on prosthetics human gaits in collaboration with well-known companies in prosthetics. Overall, our commercial goal is to build a complete product line of BCH power systems specifically tailored to the unique needs of prosthetic products. Our commercialization plan includes several other very relevant markets for the proposed technology that makes development of the technology an attractive business pursuit.